Update Android port

Update Android port

* doc/emacs/input.texi (Touchscreens): Document
`touch-screen-preview-select'.
* doc/lispref/commands.texi (Touchscreen Events): Fix typo in
the descriptions of two touch screen events.
* lisp/dired.el (dired-insert-set-properties): Adjust for
changes to file end computation.
* lisp/minibuffer.el (clear-minibuffer-message): Don't clear
minibuffer message if dragging.
* lisp/touch-screen.el (touch-screen-current-tool): Fix doc
string.
(touch-screen-preview-select): New function.
(touch-screen-drag): Call it if point changes.